William d



W. D. 'GRAVES' ELECTRIC LAMP.

Patented Sept. 9, 1890.

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UNITED STATES PATENT OFFICE.

\VILLIAM D. GRAVES, OF CLEVELAND, OHIO, ASSIGNOR OF ONE-HALF TO FRANK J. STAFFORD, OF SAME PLACE.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 435,967, dated September 9, 1890. 7 Application filed April 30, 1890- Serial No. 350,117. (No model.) 7

To all whom it may concern.-

Be it known that 1, WILLIAM D. GRAVES, of Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Electric Lamps, of which the following is a specification.

This invention relates to electric lamps, and has for its object to provide a means in a duplex lamp for the successive burning of one set of carbons after the first set has been consumed for the prolongation of the lighting from such lamp, and it also provides that a continuous and unbroken light shall be maintained throughout the burning of both sets of carbons.

In the accompanying drawings, Figure 1 is a side elevation of an electric lamp having my invention attached. Fig. 2 isatransverse side elevation of the same, showing aduplex lamp.

A represents one set of carbons, and A a second set, each sethaving independent holders B B The carbon-holders consist of rods B B of the usual kind, and each of them is connected with respective feed and holding devices 0 G These devices consist of levers G O in the form of frames, through which the carbon-holders pass, containing a train of gear-wheels and a brake-wheel, whereby the feed of the carbons is regulated.

The carbon -holders are provided 011 one side with rack-teeth b, with which a pinion c meshes. On the same shaft with said pinion is a gear-wheel c and this meshes with a pinion c on a second shaft, on which is also a brake-wheel 0 The frames 0 O are trunnioned between posts 19 p in the housing or frame-workwhich supports all the mechanism.

D D are springs secured to the posts 19 p, which bear against the brake-wheels c and by their tension and friction serve to check these two arms are provided with suitable bindingposts g h. This constitutes a switch device, and comprises the essential feature of my invention. The other parts of the lamp may be varied, and consist of any of the wellknown constructions, my improvement being designed to have but one set of carbons within the electric circuit at a time, and when the first set is consumed the second set may be switched into the circuit and the old one cut out, and this may be carried on through several sets of carbons successively for prolongation of light.

In carrying out this system I have arranged the wires substantially in the following manner: Beginning at binding-post No. 1, where connection is made with the positive side electric supply, I connect the coarse Wire of the first helix, then connect the wire to binding-post No. 2 at lower end of carbon-holder. Next I connect a wire with binding-post No. 3 at lower end of the support, and carry said wire to binding-post No. 4:, where the negative side of the electric supplyis connected. Thus a complete circuit is formed through said first helix and the first set of carbons. I also connect the fine wire of the helix below the said first helix with the said binding-posts Nos. 1 and 4:, thus establishing a circuit of greater resistance. Now the electric current passing through the first helix operates to draw up ward the core and lift the lever 0, thereby separating the carbons, and produces the vol-' taic are light. At the same time the brakewheel 0 is brought into contact with the brake-spring D, and the carbon-holder is thereby prevented from dropping suddenly, but will cause a gradual feeding down of the carbon, and thus maintain the voltaic arc. Should, however, the carbons become entirely consumed and a break or separation take place through said first carbons, the lever 0 would drop and thereby switch in the second upper helix, thereby making an electric circuit through the second lamp, and the same operation above described would be carried forward by duplicate mechanism. A derived current is still maintained through the helix F of high resistance by small wire from post No. 1 to post No. 4: of supply after thefirst carbons are consumed or the circuit through them becomes broken. The object of this is to have the said helix F exert its influence upon the lever O to firmly maintain the contact of the switch-arms G H against their becoming separated by jarring or otherwise, which would be injurious. The first set of carbons being consumed or cutout of the circuit, and the switch having closed and brought into the circuit the second carbons, the course of the electricity is as follows: From post No. 1 to helix E thence to post No. 5 through carbons A thence from post No. 6 through the wire to post h, thence up through switcharms G H, and by wire from post g to negative post No. 4. Thus the second set of carbons are brought into action for continuous lighting, and by providing a lever, as C, and arms, as G H, in connection with the second set of helices, a third set of carbons may be used to succeed the second set, and thereby make an indefinite continuation of light. A derived high-resistance current is also provided through helix F by a small Wire leading from post No. 1 to said helix, thence by Wire to post h, thence through switch-arms G H, and thence from g to No. 4:, for the same purpose as that through helix F. It will thus be seen that when the switch connected with the first lever O closes, the electric current is transferred from the first to the second lamp, and this might be carried on indefinitely by triplicating or quadruplexing my mechanism, and, in fact, a multiplex lamp be the result.

Having described my invention, What I claim is 1. In a duplex or multiplex arc lamp, the combination of double sets of solenoids, one solenoid in each set being of low resistance, carbon-holders and carbons connected in series with said lowresistance solenoids, a lever, as O, a suitable feed mechanism, and a switch-arm attached to said lever arranged within said circuit, constructed to operate substantially as and for the purpose specified.

2. In a multiplex are lamp, the combination of double sets of solenoids, one solenoid in each set being of low resistance and one set being of high resistance, carbon-holders and carbons connected in the series with said low resistances, and levers, as C, aswitch-arm, as G, mounted on said lever, and a suitable feed mechanism supported by said lever, all constructed to operate substantially as and for the purpose specified.

NILLIAM D. GRAVES.

Witnesses:

ABNER SLUTZ, GEO. W. TIBBITTs. 

